Amazon is the first place to look because of its extensive selection of both used and discounted new books. When you pull up a book you’ve searched for, be on the lookout for a button that says “Used.” Clicking this link will bring you to a page listing used copies of that book, arranged from lowest to highest price.
From here, you can look at each available used copy to see what condition it’s in and the seller’s trust rating—these used copies are being sold by other Amazon users, not by Amazon itself, so see what other buyers have had to say about the seller.
If all seems okay, go ahead and buy! Amazon routinely saves your hundreds of dollars on book costs.
The other way is to use the amazon books.com search page to find your books, you can input author name, title, ISBN, publisher to search. If you already knew something about your books, then this tool is what you need exactly.
If you still want more, then maybe can try advanced amazon books finder, it looks almost like the tool above, but has more options and can let you to find the discount books by discount range.
You also can try amazon discount finder to look for more discount deals on amazon.com.
PLAYSTATION 3 
Nintendo DS 
